Store the emulator pinning cpu mask as a pure virBitmap rather than the
virDomainPinDef since it stores only the bitmap and refactor
qemuDomainPinEmulator to do the same operations in a much saner way.
As a side effect virDomainEmulatorPinAdd and virDomainEmulatorPinDel can
be removed since they don't add any value.
https://bugzilla.redhat.com/show_bug.cgi?id=998813
Like usb-serial, the pci-serial device allows a serial device to be
attached to PCI bus. An example XML looks like this:
<serial type='dev'>
<source path='/dev/ttyS2'/>
<target type='pci-serial' port='0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
</serial>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Sometimes the only thing we need is the pointer to virDomainDiskDef and
having to call virDomainDiskIndexBy* APIs, storing the disk index, and
looking it up in the disks array is ugly. After this patch, we can just
call virDomainDiskBy* and get the pointer in one step.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=976387
For a domain configured using the host cdrom, we should taint the domain
due to problems encountered when the host and guest try to control the tray.
Two new domain configuration XML elements are added to enable/disable
the protected key management operations for a guest:
<domain>
...
<keywrap>
<cipher name='aes|dea' state='on|off'/>
</keywrap>
...
</domain>
Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Signed-off-by: Daniel Hansel <daniel.hansel@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Because there are multiple potential reasons for an error, this
function logs any errors before returning NULL (since the caller won't
have the information needed to determine which was the reason for
failure).
Until now the virDomainListAllDomains API would lock the domain list and
then every single domain object to access and filter it. This would
potentially allow a unresponsive VM to block the whole daemon if a
*listAllDomains call would get stuck.
To avoid this problem this patch collects a list of referenced domain
objects first from the list and then unlocks it right away. The
expensive operation requiring locking of the domain object is executed
after the list lock is dropped. While a single blocked domain will still
lock up a listAllDomains call, the domain list won't be held locked and
thus other APIs won't be blocked.
Additionally this patch also fixes the lookup code, where we'd ignore
the vm->removing flag and thus potentially return domain objects that
would be deleted very soon so calling any API wouldn't make sense.
As other clients also could benefit from operating on a list of domain
objects rather than the public domain descriptors a new intermediate
API - virDomainObjListCollect - is introduced by this patch.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1181074
Extend it to a universal helper used for clearing lists of any objects.
Note that the argument type is specifically void * to allow implicit
typecasting.
Additionally add a helper that works on non-NULL terminated arrays once
we know the length.
Some platforms, like aarch64, don't have APIC but GIC. So there's
no reason to have <apic/> feature turned on. However, we are
still missing <gic/> feature. This commit introduces the feature
to XML parser and formatter, adds documentation and updates RNG
schema.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
The phyp driver stuffed it into a DomainDefPtr during its attachdevice
routine, but the value is never advertised via capabilities so it should
be safe to drop.
Have the phyp driver use OSTYPE_LINUX, which is what it advertises via
capabilities.
We're about to allow IOThreads to be deleted, but an iothreadid may be
included in some domain thread sched, so add a new API to allow removing
an iothread from some entry.
Then during the writing of the threadsched data and an additional check
to determine whether the bitmap is all clear before writing it out.
Remove the iothreadspin array from cputune and replace with a cpumask
to be stored in the iothreadids list.
Adjust the test output because our printing goes in order of the iothreadids
list now.
Since it's only ever referenced in domain_conf.c, make the function
static, but also will need to move it to somewhere before it's referenced
rather than forward referencing it.
Add 'thread_id' to the virDomainIOThreadIDDef as a means to store the
'thread_id' as returned from the live qemu monitor data.
Remove the iothreadpids list from _qemuDomainObjPrivate and replace with
the new iothreadids 'thread_id' element.
Rather than use the default numbering scheme of 1..number of iothreads
defined for the domain, use the iothreadid's list for the iothread_id
Since iothreadids list keeps track of the iothread_id's, these are
now used in place of the many places where a for loop would "know"
that the ID was "+ 1" from the array element.
The new tests ensure usage of the <iothreadid> values for an exact number
of iothreads and the usage of a smaller number of <iothreadid> values than
iothreads that exist (and usage of the default numbering scheme).
Adding a new XML element 'iothreadids' in order to allow defining
specific IOThread ID's rather than relying on the algorithm to assign
IOThread ID's starting at 1 and incrementing to iothreads count.
This will allow future patches to be able to add new IOThreads by
a specific iothread_id and of course delete any exisiting IOThread.
Each iothreadids element will have 'n' <iothread> children elements
which will have attribute "id". The "id" will allow for definition
of any "valid" (eg > 0) iothread_id value.
On input, if any <iothreadids> <iothread>'s are provided, they will
be marked so that we only print out what we read in.
On input, if no <iothreadids> are provided, the PostParse code will
self generate a list of ID's starting at 1 and going to the number
of iothreads defined for the domain (just like the current algorithm
numbering scheme). A future patch will rework the existing algorithm
to make use of the iothreadids list.
On output, only print out the <iothreadids> if they were read in.
This is basically turning qemuDomObjEndAPI into a more general
function. Other drivers which gets a reference to domain objects may
benefit from this function too.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This needs to specified in way too many places for a simple validation
check. The ostype/arch/virttype validation checks later in
DomainDefParseXML should catch most of the cases that this was covering.
But the internal API stays the same, and we just convert the value as
needed. Not useful yet, but this is the beginning step of using an enum
for ostype throughout the code.
When parsing XML, we validate the passed ostype + arch combo against
the detected hypervisor capabilities. This has led to the following
problem:
- Define x86 qemu guest
- qemu is inadvertently removed from the host
- libvirtd is restarted. fails to parse VM config since arch is removed
- 'virsh list --all' is now empty, user is wondering where their VMs went
Add a new internal flag VIR_DOMAIN_DEF_PARSE_SKIP_OSTYPE_CHECKS. Use
it when loading VM and snapshot configs from disk.
https://bugzilla.redhat.com/show_bug.cgi?id=1043572
Add VIR_DOMAIN_INPUT_BUS_PARALLELS device type
to handle domain configuration properly for
parallels containers, when VNC is enabled.
When domain configuration has at least one
'graphics', there should be mouse and keyboard.
Signed-off-by: Dmitry Guryanov <dguryanov@parallels.com>
We support VNC for containers to have the same
interface with VMs. At this moment it just renders
linux text console.
Of course we don't pass any physical devices and
don't emulate virtual devices. Our VNC server
renders text from terminal master and sends
input events from VNC client to terminal.
So add special video type VIR_DOMAIN_VIDEO_TYPE_PARALLELS
for these pseudo-devices.
Signed-off-by: Dmitry Guryanov <dguryanov@parallels.com>
Instead of always using controller 0 and incrementing port number,
respect the maximum port numbers of controllers and use all of them.
Ports for virtio consoles are quietly reserved, but not formatted
(neither in XML nor on QEMU command line).
Also rejects duplicate virtio-serial addresses.
https://bugzilla.redhat.com/show_bug.cgi?id=890606https://bugzilla.redhat.com/show_bug.cgi?id=1076708
Test changes:
* virtio-auto.args
Filling out the port when just the controller is specified.
switched from using
maxport + 1
to:
first free port on the controller
* virtio-autoassign.args
Filling out the address when no <address> is specified.
Started using all the controllers instead of 0, also discards
the bus value.
* xml -> xml output of virtio-auto
The port assignment is no longer done as a part of XML parsing,
so the unspecified values stay 0.
virDomainHasDiskMirror() currently detects only jobs that add the mirror
elements. Since some operations like migration are interlocked by
existing block jobs on the given domain the check needs to be
instrumented to check regular jobs too.
This patch renames virDomainHasDiskMirror to virDomainHasDiskBlockjob
and adds an argument that allows to select that it returns true only for
block copy jobs as those interlock making the domain persistent.
Other two uses trigger on any block job type.
Signed-off-by: Shanzhi Yu <shyu@redhat.com>
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
When the synchronous pivot option is selected, libvirt would not update
the backing chain until the job was exitted. Some applications then
received invalid data as their job serialized first.
This patch removes polling to wait for the ABORT/PIVOT job completion
and replaces it with a condition. If a synchronous operation is
requested the update of the XML is executed in the job of the caller of
the synchronous request. Otherwise the monitor event callback uses a
separate worker to update the backing chain with a new job.
This is a regression since 1a92c71910
When the ABORT job is finished synchronously you get the following call
stack:
#0 qemuBlockJobEventProcess
#1 qemuDomainBlockJobImpl
#2 qemuDomainBlockJobAbort
#3 virDomainBlockJobAbort
While previously or while using the _ASYNC flag you'd get:
#0 qemuBlockJobEventProcess
#1 processBlockJobEvent
#2 qemuProcessEventHandler
#3 virThreadPoolWorker
Recently we've fixed a bug where the status XML could not be parsed as
the parser used absolute path XPath queries. This test enhancement tests
all XML files used in the qemu-xml-2-xml test as a part of a status XML
snippet to see whether they are parsed correctly. The status XML-2-XML is
currently tested in 223 cases with this patch.
Add a few helpers that allow to operate with memory device definitions
on the domain config and use them to implement memory device coldplug in
the qemu driver.
This patch adds code that parses and formats configuration for memory
devices.
A simple configuration would be:
<memory model='dimm'>
<target>
<size unit='KiB'>524287</size>
<node>0</node>
</target>
</memory>
A complete configuration of a memory device:
<memory model='dimm'>
<source>
<pagesize unit='KiB'>4096</pagesize>
<nodemask>1-3</nodemask>
</source>
<target>
<size unit='KiB'>524287</size>
<node>1</node>
</target>
</memory>
This patch preemptively forbids use of the <memory> device in individual
drivers so the users are warned right away that the device is not
supported.
Add a XML element that will allow to specify maximum supportable memory
and the count of memory slots to use with memory hotplug.
To avoid possible confusion and misuse of the new element this patch
also explicitly forbids the use of the maxMemory setting in individual
drivers's post parse callbacks. This limitation will be lifted when the
support is implemented.
virnetdevopenvswitch.h declares a few functions that can be called to
add ports to and remove them from OVS bridges, and retrieve the
migration data for a port. It does not contain any data definitions
that are used by domain_conf.h. But for some reason, domain_conf.h
virnetdevopenvswitch.h should be directly #including it. This adds a
few lines to the project, but saves all the files that don't need it
from the extra computing, and makes the dependencies more clear cut.
We're parsing memballoon status period as unsigned int, but when we're
trying to set it, both we and qemu use signed int. That means large
values will get wrapped around to negative one resulting in error.
Basically the same problem as commit e3a7b874 was dealing with when
updating live domain.
QEMU changed the accepted value to int64 in commit 1f9296b5, but even
values as INT_MAX don't make sense since the value passed means seconds.
Hence adding capability flag for this change isn't worth it.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1140958
Signed-off-by: Luyao Huang <lhuang@redhat.com>
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
As pointed out by jtomko in his review of the IOThreads pinning code:
http://www.redhat.com/archives/libvir-list/2015-March/msg00495.html
there are some comments sprinkled in indicating IOThreads were using
the same structure as the VcpuPin code...
This is the first patch of a few that will change the virDomainVcpuPin*
structures and code to just virDomainPin* - starting with the data
structure naming...
As there are two possible approaches to define a domain's memory size -
one used with legacy, non-NUMA VMs configured in the <memory> element
and per-node based approach on NUMA machines - the user needs to make
sure that both are specified correctly in the NUMA case.
To avoid this burden on the user I'd like to replace the NUMA case with
automatic totaling of the memory size. To achieve this I need to replace
direct access to the virDomainMemtune's 'max_balloon' field with
two separate getters depending on the desired size.
The two sizes are needed as:
1) Startup memory size doesn't include memory modules in some
hypervisors.
2) After startup these count as the usable memory size.
Note that the comments for the functions are future aware and document
state that will be present after a few later patches.
virDomainNetFindIdx no longer returns info whether device was not found,
or there was multiple matches. Additionally it already handle error
reporting. Introduce virDomainHasNet which does a simple task, without
implicit error reporting.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1135491
More or less a virtual copy of the existing virDomainVcpuPin{Add|Del} API's.
NB: The IOThreads implementation "reused" the virDomainVcpuPinDefPtr
since it provided everything necessary - an "id" and a "map" for each
thread id configured.
Since adding the support for scheduler policy settings in commit
8680ea97, there are two enums with the same information. That was
caused by rewriting the patch since first draft.
Find out thanks to clang, but there was no impact whatsoever.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1142631
This patch resolves a situation where the same "<target dev='$name'...>"
can be used for multiple disks in the domain.
While the $name is "mostly" advisory regarding the expected order that
the disk is added to the domain and not guaranteed to map to the device
name in the guest OS, it still should be unique enough such that other
domblk* type operations can be performed.
Without the patch, the domblklist will list the same Target twice:
$ virsh domblklist $dom
Target Source
------------------------------------------------
sda /var/lib/libvirt/images/file.qcow2
sda /var/lib/libvirt/images/file.img
Additionally, getting domblkstat, domblkerror, domblkinfo, and other block*
type calls will not be able to reference the second target.
Fortunately, hotplug disallows adding a "third" sda value:
$ qemu-img create -f raw /var/lib/libvirt/images/file2.img 10M
$ virsh attach-disk $dom /var/lib/libvirt/images/file2.img sda
error: Failed to attach disk
error: operation failed: target sda already exists
$
BUT, it since 'sdb' doesn't exist one would get the following on the same
hotplug attempt, but changing to use 'sdb' instead of 'sda'
$ virsh attach-disk $dom /var/lib/libvirt/images/file2.img sdb
error: Failed to attach disk
error: internal error: unable to execute QEMU command 'device_add': Duplicate ID 'scsi0-0-1' for device
$
Since we cannot fix this issue at parsing time, the best that can be done so
as to not "lose" a domain is to make the check prior to starting the guest
with the results as follows:
$ virsh start $dom
error: Failed to start domain $dom
error: XML error: target 'sda' duplicated for disk sources '/var/lib/libvirt/images/file.qcow2' and '/var/lib/libvirt/images/file.img'
$
Running 'make check' found a few more instances in the tests where this
duplicated target dev value was being used. These also exhibited some
duplicated 'id=' values (negating the uniqueness argument of aliases) in
the corresponding .args file and of course the *xmlout version of a few
input XML files.
At least Xen supports backend drivers in another domain (aka "driver
domain"). This patch introduces an XML config option for specifying the
backend domain name for <disk> and <interface> devices. E.g.
<disk>
<backenddomain name='diskvm'/>
...
</disk>
<interface type='bridge'>
<backenddomain name='netvm'/>
...
</interface>
In the future, same option will be needed for USB devices (hostdev
objects), but for now libxl doesn't have support for PVUSB.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Move the existing virDomainDefNew to virDomainDefNewFull as it's setting
a few things in the conf and re-introduce virDomainDefNew as a function
without parameters for common use.
For a while now there are two places that gather information about NUMA
related guest configuration. While the XML can't be changed we can at
least store the data in one place in the definition.
Rename the numatune_conf.[ch] files to numa_conf as later patches will
move the rest of the definitions from the cpu definition to this one.
Add an XML attribute to allow disabling merge of rx buffers
on the host:
<interface ...>
...
<model type='virtio'/>
<driver ...>
<host mrg_rxbuf='off'/>
</driver>
</interface>
https://bugzilla.redhat.com/show_bug.cgi?id=1186886
In order for QEMU vCPU (and other) threads to run with RT scheduler,
libvirt needs to take care of that so QEMU doesn't have to run privileged.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1178986
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
The helpers will be useful when implementing hotplug and coldplug of
random number generator devices.
Signed-off-by: Luyao Huang <lhuang@redhat.com>
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
When adding devices to the definition it's useful to check whether the
devices don't reside on a conflicting address. This patch adds a helper
that iterates all device info and compares the addresses with the given
info.
Do the allocation first, then add the actual device.
The second part should never fail. This is good
for live hotplug where we don't want to remove the device
on OOM after the monitor command succeeded.
The only change in behavior is that on failure, the
vmdef->consoles array is freed, not just the first console.
Currently when launching the LXC controller we first write out
the plain, inactive XML configuration, then launch the controller,
then replace the file with the live status XML configuration.
By good fortune this hasn't caused any problems other than some
misleading error messages during failure scenarios.
This simplifies the code so it only writes out the XML once and
always writes the live status XML. To do this we need to handshake
with the child process, to make execution pause just before exec()
so we can write the XML status with the child PID present.
Ploop is a pseudo device which makeit possible to access
to an image in a file as a block device. Like loop devices,
but with additional features, like snapshots, write tracker
and without double-caching.
It used in PCS for containers and in OpenVZ. You can manage
ploop devices and images with ploop utility
(http://git.openvz.org/?p=ploop).
Signed-off-by: Dmitry Guryanov <dguryanov@parallels.com>
The virDomainDefineXMLFlags and virDomainCreateXML APIs both
gain new flags allowing them to be told to validate XML.
This updates all the drivers to turn on validation in the
XML parser when the flags are set
The virDomainDefParse* and virDomainDefFormat* methods both
accept the VIR_DOMAIN_XML_* flags defined in the public API,
along with a set of other VIR_DOMAIN_XML_INTERNAL_* flags
defined in domain_conf.c.
This is seriously confusing & error prone for a number of
reasons:
- VIR_DOMAIN_XML_SECURE, VIR_DOMAIN_XML_MIGRATABLE and
VIR_DOMAIN_XML_UPDATE_CPU are only relevant for the
formatting operation
- Some of the VIR_DOMAIN_XML_INTERNAL_* flags only apply
to parse or to format, but not both.
This patch cleanly separates out the flags. There are two
distint VIR_DOMAIN_DEF_PARSE_* and VIR_DOMAIN_DEF_FORMAT_*
flags that are used by the corresponding methods. The
VIR_DOMAIN_XML_* flags received via public API calls must
be converted to the VIR_DOMAIN_DEF_FORMAT_* flags where
needed.
The various calls to virDomainDefParse which hardcoded the
use of the VIR_DOMAIN_XML_INACTIVE flag change to use the
VIR_DOMAIN_DEF_PARSE_INACTIVE flag.
Add the possibility to have more than one IP address configured for a
domain network interface. IP addresses can also have a prefix to define
the corresponding netmask.
Currently, when there is an API that's blocking with locked domain and
second API that's waiting in virDomainObjListFindByUUID() for the domain
lock (with the domain list locked) no other API can be executed on any
domain on the whole hypervisor because all would wait for the domain
list to be locked. This patch adds new optional approach to this in
which the domain is only ref'd (reference counter is incremented)
instead of being locked and is locked *after* the list itself is
unlocked. We might consider only ref'ing the domain in the future and
leaving locking on particular APIs, but that's no tonight's fairy tale.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
When one domain is being undefined and at the same time started, for
example, there is a possibility of a rare problem occuring.
- Thread 1 does virDomainUndefine(), has the lock, checks that the
domain is active and because it's not, calls
virDomainObjListRemove().
- Thread 2 does virDomainCreate() and tries to lock the domain.
- Thread 1 needs to lock domain list in order to remove the domain from
it, but must unlock domain first (proper order is to lock domain list
first and the domain itself second).
- Thread 2 grabs the lock, starts the domain and releases the lock.
- Thread 1 grabs the lock and removes the domain from list.
With this patch:
- The undefining domain gets marked as "to undefine" before it is
unlocked.
- If domain is found in any of the search APIs, it's returned only if
it is not marked as "to undefine". The check is done while the
domain is locked.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1150505
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
At the time that the network driver allocates a connection to a
network, the tap device that will be used hasn't yet been created -
that will be done later by qemu (or lxc or whoever) - but if the
network has macTableManager='libvirt', then when we do get around to
creating the tap device, we will need to add an entry for it to the
network bridge's fdb (forwarding database) *and* turn off learning and
unicast_flood for that tap device in the bridge's sysfs settings. This
means that qemu needs to know both the bridge name as well as the
setting of macTableManager, so we either need to create a new API to
retrieve that info, or just pass it back in the ActualNetDef that is
created during networkAllocateActualDevice. We choose the latter
method, since it's already done for the bridge device, and it has the
side effect of making the information available in domain status.
(NB: in the future, I think that the tap device should actually be
created by networkAllocateActualDevice(), as that will solve several
other problems, but that is a battle for another day, and this
information will still be useful outside the network driver)
Resolving symlinks can fail before mounting any file system if one file
system depends on another being mounted. Symlinks are now resolved in
two passes:
* Before any file system is mounted, but then we are more gentle if
the source path can't be accessed
* Right before mounting a file system, so that we are sure that we
have the resolved path... but then if it can't be accessed we raise
an error.
Add attribute to set vgamem_mb parameter of QXL device for QEMU. This
value sets the size of VGA framebuffer for QXL device. Default value in
QEMU is 8MB so reuse it also in libvirt to not break things.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1076098
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
The vram attribute was introduced to set the video memory but it is
usable only for few hypervisors excluding QEMU/KVM and the old XEN
driver. Only in case of QEMU the vram was used for QXL.
This patch updates the documentation to reflect current code in libvirt
and also changes the cases when we will set the default vram attribute.
It also fixes existing strange default value for VGA devices 9MB to 16MB
because the video ram should be rounded to power of two.
The change of default value could affect migrations but I found out that
QEMU always round the video ram to power of two internally so it's safe
to change the default value to the next closest power of two and also
silently correct every domain XML definition. And it's also safe because
we don't pass the value to QEMU.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1076098
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Get mounted filesystems list, which contains hardware info of disks and its
controllers, from QEMU guest agent 2.2+. Then, convert the hardware info
to corresponding device aliases for the disks.
Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com>
Some storage systems have internal support for snapshots. Libvirt should
be able to select a correct snapshot when starting a VM.
This patch adds a XML element to select a storage source snapshot for
the RBD protocol which supports this feature.
To track state of virtio channels this patch adds a new output-only
attribute called 'state' to the <target> element of virtio channels.
This will be later populated with the guest state of the channel.
Modify the structure _virDomainBlockIoTuneInfo to support these the new
options.
Change the initialization of the variable expectedInfo in qemumonitorjsontest.c
to avoid compiling problem.
Add documentation about the new xml options
Signed-off-by: Matthias Gatto <matthias.gatto@outscale.com>
Commit 01b4de2b9f abstracts virDomainParseMemory()
for use by other functions in domain_conf.c
Extend the same for use, for functions outside of this file.
Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Commit 6c9a8a4 (Oct 2014) exposed a long-standing issue on 32-bit
machines: code related to virDomainSetMemoryParameters has always
been documented as using a 64-bit limit, but it was implemented by
calling virDomainParseMemory which enforced an 'unsigned long'
limit. Since VIR_DOMAIN_MEMORY_PARAM_UNLIMITED capped to a
long is -1, but virDomainParseScaledValue no longer accepts
negative values, an attempt to use 2^53-1 as a hard memory limit
started failing the testsuite. However, the problem with capping
things artificially low has existed for much longer - ever since
commits 4888f0fb and 2e22f23 (Mar 2012) switched internal tracking
from 'unsigned long' to 'unsigned long long' (prior to that time,
the cap was a side-effect of the choice of types). We _have_ to
cap the balloon memory values, (no thanks to baked in 'unsigned long'
of API such as virDomainSetMaxMemory or virDomainGetInfo with no
counterpart API that guarantees 64-bit access to those numbers)
but memory parameters have never needed the artificial limit.
At any rate, the solution is to make the parser function gain a
parameter, and only do the reduced 32-bit cap for the values that
are constrained due to API.
* src/conf/domain_conf.h (_virDomainMemtune): Add comments.
* src/conf/domain_conf.c (virDomainParseMemory): Add parameter.
(virDomainDefParseXML): Adjust callers.
Signed-off-by: Eric Blake <eblake@redhat.com>
This new attribute will control whether or not libvirt will pay
attention to guest notifications about changes to network device mac
addresses and receive filters. The default for this is 'no' (for
security reasons). If it is set to 'yes' *and* the specified device
model and connection support it (currently only macvtap+virtio) then
libvirt will watch for NIC_RX_FILTER_CHANGED events, and when it
receives one, it will issue a query-rx-filter command, retrieve the
result, and modify the host-side macvtap interface's mac address and
unicast/multicast filters accordingly.
The functionality behind this attribute will be in a later patch. This
patch merely adds the attribute to the top-level of a domain's
<interface> as well as to <network> and <portgroup>, and adds
documentation and schema/xml2xml tests. Rather than adding even more
test files, I've just added the net attribute in various applicable
places of existing test files.
This patch adds parsing/formatting code as well as documentation for
shared memory devices. This will currently be only accessible in QEMU
using it's ivshmem device, but is designed as generic as possible to
allow future expansion for other hypervisors.
In the devices section in the domain XML users may specify:
- For shmem device using a server:
<shmem name='shmem0'>
<server path='/tmp/socket-ivshmem0'/>
<size unit='M'>32</size>
<msi vectors='32' ioeventfd='on'/>
</shmem>
- For ivshmem device not using an ivshmem server:
<shmem name='shmem1'>
<size unit='M'>32</size>
</shmem>
Most of the configuration is made optional so it also allows
specifications like:
<shmem name='shmem1/>
<shmem name='shmem2'>
<server/>
</shmem>
Signed-off-by: Maxime Leroy <maxime.leroy@6wind.com>
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Add options for tuning segment offloading:
<driver>
<host csum='off' gso='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
<guest csum='off' tso4='off' tso6='off' ecn='off' ufo='off'/>
</driver>
which control the respective host_ and guest_ properties
of the virtio-net device.
Cleanup virDomanDef structure from other nested structure and create
separate type definition for them.
Fix a typo in virDomainHugePage.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
For tuning the network, alternative devices
for creating tap and vhost devices can be specified via:
<backend tap='/dev/net/tun' vhost='/dev/net-vhost'/>
https://bugzilla.redhat.com/show_bug.cgi?id=1101574
Add an option 'iothreadpin' to the <cpuset> to allow for setting the
CPU affinity for each IOThread.
The iothreadspin will mimic the vcpupin with respect to being able to
assign each iothread to a specific CPU, although iothreads ids start
at 1 while vcpu ids start at 0. This matches the iothread naming scheme.
When using split UEFI image, it may come handy if libvirt manages per
domain _VARS file automatically. While the _CODE file is RO and can be
shared among multiple domains, you certainly don't want to do that on
the _VARS file. This latter one needs to be per domain. So at the
domain startup process, if it's determined that domain needs _VARS
file it's copied from this master _VARS file. The location of the
master file is configurable in qemu.conf.
Temporary, on per domain basis the location of master NVRAM file can
be overridden by this @template attribute I'm inventing to the
<nvram/> element. All it does is holding path to the master NVRAM file
from which local copy is created. If that's the case, the map in
qemu.conf is not consulted.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Up to now, users can configure BIOS via the <loader/> element. With
the upcoming implementation of UEFI this is not enough as BIOS and
UEFI are conceptually different. For instance, while BIOS is ROM, UEFI
is programmable flash (although all writes to code section are
denied). Therefore we need new attribute @type which will
differentiate the two. Then, new attribute @readonly is introduced to
reflect the fact that some images are RO.
Moreover, the OVMF (which is going to be used mostly), works in two
modes:
1) Code and UEFI variable store is mixed in one file.
2) Code and UEFI variable store is separated in two files
The latter has advantage of updating the UEFI code without losing the
configuration. However, in order to represent the latter case we need
yet another XML element: <nvram/>. Currently, it has no additional
attributes, it's just a bare element containing path to the variable
store file.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
The new blockcopy API wants to reuse only a subset of the disk
hotplug parser - namely, we only care about the embedded
virStorageSourcePtr inside a <disk> XML. Strange as it may
seem, it was easier to just parse an entire disk definition,
then throw away everything but the embedded source, than it
was to disentangle the source parsing code from the rest of
the overall disk parsing function. All that I needed was a
couple of tweaks and a new internal flag that determines
whether the normally-mandatory target element can be
gracefully skipped, since everything else was already optional.
* src/conf/domain_conf.h (virDomainDiskSourceParse): New
prototype.
* src/conf/domain_conf.c (VIR_DOMAIN_XML_INTERNAL_DISK_SOURCE):
New flag.
(virDomainDiskDefParseXML): Honor flag to make target optional.
(virDomainDiskSourceParse): New function.
Signed-off-by: Eric Blake <eblake@redhat.com>
Add a new disk "driver" attribute "iothread" to be parsed as the thread
number for the disk to use. In order to more easily facilitate the usage
and configuration of the iothread, a "zero" for the attribute indicates
iothreads are not supported for the device and a positive value indicates
the specific thread to try and use.
Introduce XML to allowing adding iothreads to the domain. These can be
used by virtio-blk-pci devices in order to assign a specific thread to
handle the workload for the device. The iothreads are the official
implementation of the virtio-blk Data Plane that's been in tech preview
for QEMU.
QEMU 2.1 added support for the kvm=off option to the -cpu command,
allowing the KVM hypervisor signature to be hidden from the guest.
This enables disabling of some paravirualization features in the
guest as well as allowing certain drivers which test for the
hypervisor to load. Domain XML syntax is as follows:
<domain type='kvm>
...
<features>
...
<kvm>
<hidden state='on'/>
</kvm>
</features>
...
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
A future patch is going to wire up qemu active block commit jobs;
but as they have similar events and are canceled/pivoted in the
same way as block copy jobs, it is easiest to track all bookkeeping
for the commit job by reusing the <mirror> element. This patch
adds domain XML to track which job was responsible for creating a
mirroring situation, and adds a job='copy' attribute to all
existing uses of <mirror>. Along the way, it also massages the
qemu monitor backend to read the new field in order to generate
the correct type of libvirt job (even though it requires a
future patch to actually cause a qemu event that can be reported
as an active commit). It also prepares to update persistent XML
to match changes made to live XML when a copy completes.
* docs/schemas/domaincommon.rng: Enhance schema.
* docs/formatdomain.html.in: Document it.
* src/conf/domain_conf.h (_virDomainDiskDef): Add a field.
* src/conf/domain_conf.c (virDomainBlockJobType): String conversion.
(virDomainDiskDefParseXML): Parse job type.
(virDomainDiskDefFormat): Output job type.
* src/qemu/qemu_process.c (qemuProcessHandleBlockJob): Distinguish
active from regular commit.
* src/qemu/qemu_driver.c (qemuDomainBlockCopy): Set job type.
(qemuDomainBlockPivot, qemuDomainBlockJobImpl): Clean up job type
on completion.
* tests/qemuxml2xmloutdata/qemuxml2xmlout-disk-mirror-old.xml:
Update tests.
* tests/qemuxml2argvdata/qemuxml2argv-disk-mirror.xml: Likewise.
* tests/qemuxml2argvdata/qemuxml2argv-disk-active-commit.xml: New
file.
* tests/qemuxml2xmltest.c (mymain): Drive new test.
Signed-off-by: Eric Blake <eblake@redhat.com>
Doing a blockcopy operation across a libvirtd restart is not very
robust at the moment. In particular, we are clearing the <mirror>
element prior to telling qemu to finish the job. Also, thanks to the
ability to request async completion, the user can easily regain
control prior to qemu actually finishing the effort, and they should
be able to poll the domain XML to see if the job is still going.
A future patch will fix things to actually wait until qemu is done
before modifying the XML to reflect the job completion. But since
qemu issues identical BLOCK_JOB_COMPLETE events regardless of whether
the job was cancelled (kept the original disk) or completed (pivoted
to the new disk), we have to track which of the two operations were
used to end the job. Furthermore, we'd like to avoid attempts to
end a job where we are already waiting on an earlier request to qemu
to end the job. Likewise, if we miss the qemu event (perhaps because
it arrived during a libvirtd restart), we still need enough state
recorded to be able to determine how to modify the domain XML once
we reconnect to qemu and manually learn whether the job still exists.
Although this patch doesn't actually fix the problem, it is a
preliminary step that makes it possible to track whether a job
has already begun steps towards completion.
* src/conf/domain_conf.h (virDomainDiskMirrorState): New enum.
(_virDomainDiskDef): Convert bool mirroring to new enum.
* src/conf/domain_conf.c (virDomainDiskDefParseXML)
(virDomainDiskDefFormat): Handle new values.
* src/qemu/qemu_process.c (qemuProcessHandleBlockJob): Adjust
client.
* src/qemu/qemu_driver.c (qemuDomainBlockPivot)
(qemuDomainBlockJobImpl): Likewise.
* docs/schemas/domaincommon.rng (diskMirror): Expose new values.
* docs/formatdomain.html.in (elementsDisks): Document it.
* tests/qemuxml2argvdata/qemuxml2argv-disk-mirror.xml: Test it.
Signed-off-by: Eric Blake <eblake@redhat.com>
Create the structures and API's to hold and manage the iSCSI host device.
This extends the 'scsi_host' definitions added in commit id '5c811dce'.
A future patch will add the XML parsing, but that code requires some
infrastructure to be in place first in order to handle the differences
between a 'scsi_host' and an 'iSCSI host' device.
Split virDomainHostdevSubsysSCSI further. In preparation for having
either SCSI or iSCSI data, create a union in virDomainHostdevSubsysSCSI
to contain just a virDomainHostdevSubsysSCSIHost to describe the
'scsi_host' host device
This patch adds back the virDomainDef typedef into domain_conf and
makes all the numatune_conf functions independent of any virDomainDef
definitions.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1122205
Although the edits were changing in-memory XML, it was not flushed
to disk; so unless some other action changes XML, a libvirtd restart
would lose the changed information.
* src/conf/domain_conf.c (virDomainObjSetMetadata): Add parameter,
to save live status across restarts.
(virDomainSaveXML): Allow for test driver.
* src/conf/domain_conf.h (virDomainObjSetMetadata): Adjust
signature.
* src/bhyve/bhyve_driver.c (bhyveDomainSetMetadata): Adjust caller.
* src/lxc/lxc_driver.c (lxcDomainSetMetadata): Likewise.
* src/qemu/qemu_driver.c (qemuDomainSetMetadata): Likewise.
* src/test/test_driver.c (testDomainSetMetadata): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Added <capabilities> in the <features> section of LXC domains
configuration. This section can contain elements named after the
capabilities like:
<mknod state="on"/>, keep CAP_MKNOD capability
<sys_chroot state="off"/> drop CAP_SYS_CHROOT capability
Users can restrict or give more capabilities than the default using
this mechanism.
LXC network devices can now be assigned a custom NIC device name on the
container side. For example, this is configured with:
<interface type='network'>
<source network='default'/>
<guest dev="eth1"/>
</interface>
In this example the network card will appear as eth1 in the guest.
Commit 93e82727 introduced numatune_conf.h file that contains
typedefs already defined in domain_conf.h, such as:
- virDomainNumatune
- virDomainNumatunePtr
- virDomainDef
- virDomainDefPtr
As numatune_conf.h is included by domain_conf.h, clang
complains about redefinition of typedef and the build fails.
In order to fix it, drop typedefs already defined by numatume_conf.h
from domain_conf.h.
There were numerous places where numatune configuration (and thus
domain config as well) was changed in different ways. On some
places this even resulted in persistent domain definition not to be
stable (it would change with daemon's restart).
In order to uniformly change how numatune config is dealt with, all
the internals are now accessible directly only in numatune_conf.c and
outside this file accessors must be used.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Since there was already public virDomainNumatune*, I changed the
private virNumaTune to match the same, so all the uses are unified and
public API is kept:
s/vir\(Domain\)\?Numa[tT]une/virDomainNumatune/g
then shrunk long lines, and mainly functions, that were created after
that:
sed -i 's/virDomainNumatuneMemPlacementMode/virDomainNumatunePlacement/g'
And to cope with the enum name, I haad to change the constants as
well:
s/VIR_NUMA_TUNE_MEM_PLACEMENT_MODE/VIR_DOMAIN_NUMATUNE_PLACEMENT/g
Last thing I did was at least a little shortening of already long
name:
s/virDomainNumatuneDef/virDomainNumatune/g
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
There are many places with numatune-related code that should be put
into special numatune_conf and this patch creates a basis for that.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
This patch adds support for the QEMU vhost-user feature to libvirt.
vhost-user enables the communication between a QEMU virtual machine
and other userspace process using the Virtio transport protocol.
It uses a char dev (e.g. Unix socket) for the control plane,
while the data plane based on shared memory.
The XML looks like:
<interface type='vhostuser'>
<mac address='52:54:00:3b:83:1a'/>
<source type='unix' path='/tmp/vhost.sock' mode='server'/>
<model type='virtio'/>
</interface>
Signed-off-by: Michele Paolino <m.paolino@virtualopensystems.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
In the future we might need to track state of individual images. Move
the readonly and shared flags to the virStorageSource struct so that we
can keep them in a per-image basis.
This introduces two new attributes "cmd_per_lun" and "max_sectors" same
with the names QEMU uses for virtio-scsi. An example of the XML:
<controller type='scsi' index='0' model='virtio-scsi' cmd_per_lun='50'
max_sectors='512'/>
The corresponding QEMU command line:
-device virtio-scsi-pci,id=scsi0,cmd_per_lun=50,max_sectors=512,
bus=pci.0,addr=0x3
Signed-off-by: Mike Perez <thingee@gmail.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
When looking for a port to allocate, the port allocator didn't take in
consideration ports that are statically set by the user. Defining
these two graphics elements in the XML would cause an error, as the
port allocator would try to use the same port for the spice graphics
element:
<graphics type='spice' autoport='yes'/>
<graphics type='vnc' port='5900' autoport='no'/>
The new *[pP]ortReserved variables keep track of the ports that were
successfully tracked as used by the port allocator but that weren't
bound.
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1081881
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
The image labels are stored in the virStorageSource struct. Convert the
virDomainDiskDefGetSecurityLabelDef helper not to use the full disk def
and move it appropriately.
The current implementation of 'virsh blockcopy' (virDomainBlockRebase)
is limited to copying to a local file name. But future patches want
to extend it to also copy to network disks. This patch converts over
to a virStorageSourcePtr, although it should have no semantic change
visible to the user, in anticipation of those future patches being
able to use more fields for non-file destinations.
* src/conf/domain_conf.h (_virDomainDiskDef): Change type of
mirror information.
* src/conf/domain_conf.c (virDomainDiskDefParseXML): Localize
mirror parsing into new object.
(virDomainDiskDefFormat): Adjust clients.
* src/qemu/qemu_domain.c (qemuDomainDeviceDefPostParse):
Likewise.
* src/qemu/qemu_driver.c (qemuDomainBlockPivot)
(qemuDomainBlockJobImpl, qemuDomainBlockCopy): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
As part of the work on backing chains, I'm finding that it would
be easier to directly manipulate chains of pointers (adding a
snapshot merely adjusts pointers to form the correct list) rather
than copy data from one struct to another. This patch converts
domain disk source to be a pointer.
In this patch, the pointer is ALWAYS allocated (thanks in part to
the previous patch forwarding all disk def allocation through a
common point), and all other changse are just mechanical fallout of
the new type; there should be no functional change. It is possible
that we may want to leave the pointer NULL for a cdrom with no
medium in a later patch, but as that requires a closer audit of the
source to ensure we don't fault on a null dereference, I didn't do
it here.
* src/conf/domain_conf.h (_virDomainDiskDef): Change type of src.
* src/conf/domain_conf.c: Adjust all clients.
* src/security/security_selinux.c: Likewise.
* src/qemu/qemu_domain.c: Likewise.
* src/qemu/qemu_command.c: Likewise.
* src/qemu/qemu_conf.c: Likewise.
* src/qemu/qemu_process.c: Likewise.
* src/qemu/qemu_migration.c: Likewise.
* src/qemu/qemu_driver.c: Likewise.
* src/lxc/lxc_driver.c: Likewise.
* src/lxc/lxc_controller.c: Likewise.
* tests/securityselinuxlabeltest.c: Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
A future patch wants to create disk definitions with non-zero
default contents; to avoid crashes, all callers that allocate
a disk definition should go through a common point.
I found allocation points by looking for any code that increments
ndisks, as well as any matches for ALLOC.*disk. Most places that
modified ndisks were covered by the parse from XML to domain/device
definition by initial domain creation or device hotplug; I also
hand-checked all drivers that generate a device struct on the
fly during getXMLDesc.
* src/conf/domain_conf.h (virDomainDiskDefNew): New prototype.
* src/conf/domain_conf.c (virDomainDiskDefNew): New function.
(virDomainDiskDefParseXML): Use it.
* src/parallels/parallels_driver.c (parallelsAddHddInfo):
Likewise.
* src/qemu/qemu_command.c (qemuParseCommandLine): Likewise.
* src/vbox/vbox_tmpl.c (vboxDomainGetXMLDesc): Likewise.
* src/vmx/vmx.c (virVMXParseDisk): Likewise.
* src/xenxs/xen_sxpr.c (xenParseSxprDisks, xenParseSxpr):
Likewise.
* src/xenxs/xen_xm.c (xenParseXM): Likewise.
* src/libvirt_private.syms (domain_conf.h): Export it.
Signed-off-by: Eric Blake <eblake@redhat.com>
In "src/conf/domain_conf.h" there are many enum declarations. The
cleanup in this header filer was started, but it wasn't enough and
there are many other files that has enum variables declared. So, the
commit was starting to be big. This commit finish the cleanup in this
header file and in other files that has enum variables, parameters,
or functions declared.
Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
In "src/conf/domain_conf.h" there are many enumerations (enum)
declarations to be converted as a typedef too. As mentioned before,
it's better to use a typedef for variable types, function types and
other usages. I think this file has most of those enum declarations
at "src/conf/". So, me and Eric Blake plan to keep the cleanups all
over the source code. This time, most of the files changed in this
commit are related to part of one file: "src/conf/domain_conf.h".
Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
commit e31b5cf393 attempted to fix libvirt's
VIR_DOMAIN_EVENT_ID_RTC_CHANGE, which is documentated to always
provide the new offset of the domain's real time clock from UTC. The
problem was that, in the case that qemu is provided with an "-rtc
base=x" where x is an absolute time (rather than "utc" or
"localtime"), the offset sent by qemu's RTC_CHANGE event is *not* the
new offset from UTC, but rather is the sum of all changes to the
domain's RTC since it was started with base=x.
So, despite what was said in commit e31b5cf393, if we assume that
the original value stored in "adjustment" was the offset from UTC at
the time the domain was started, we can always determine the current
offset from UTC by simply adding the most recent (i.e. current) offset
from qemu to that original adjustment.
This patch accomplishes that by storing the initial adjustment in the
domain's status as "adjustment0". Each time a new RTC_CHANGE event is
received from qemu, we simply add adjustment0 to the value sent by
qemu, store that as the new adjustment, and forward that value on to
any event handler.
This patch (*not* e31b5cf393, which should be reverted prior to
applying this patch) fixes:
https://bugzilla.redhat.com/show_bug.cgi?id=964177
(for the case where basis='utc'. It does not fix basis='localtime')
This reverts commit e31b5cf393.
This commit attempted to work around a bug in the offset value
reported by qemu's RTC_CHANGE event in the case that a variable base
date was given on the qemu commandline. The patch mixed up the math
involved in arriving at the corrected offset to report, and in the
process added an unnecessary private attribute to the clock
element. Since that element is private/internal and not used by anyone
else, it makes sense to simplify things by removing it.
The VIR_ENUM_DECL/VIR_ENUM_IMPL helper macros already append 'Type'
to the enum name being converted; it looks silly to have functions
with 'TypeType' in their name. Even though some of our enums have
to have a 'Type' suffix, the corresponding string conversion
functions do not.
* src/conf/secret_conf.h (VIR_ENUM_DECL): Rename virSecretUsageType.
* src/conf/storage_conf.h (VIR_ENUM_DECL): Rename
virStoragePoolAuthType, virStoragePoolSourceAdapterType,
virStoragePartedFsType.
* src/conf/domain_conf.c (virDomainDiskDefParseXML)
(virDomainFSDefParseXML, virDomainFSDefFormat): Update callers.
* src/conf/secret_conf.c (virSecretDefParseUsage)
(virSecretDefFormatUsage): Likewise.
* src/conf/storage_conf.c (virStoragePoolDefParseAuth)
(virStoragePoolDefParseSource, virStoragePoolSourceFormat):
Likewise.
* src/lxc/lxc_controller.c (virLXCControllerSetupLoopDevices):
Likewise.
* src/storage/storage_backend_disk.c
(virStorageBackendDiskPartFormat): Likewise.
* src/util/virstorageencryption.c (virStorageEncryptionSecretParse)
(virStorageEncryptionSecretFormat): Likewise.
* tools/virsh-secret.c (cmdSecretList): Likewise.
* src/libvirt_private.syms (secret_conf.h, storage_conf.h): Export
corrected names.
Signed-off-by: Eric Blake <eblake@redhat.com>
In "src/conf/" there are many enumeration (enum) declarations.
Similar to the recent cleanup to "src/util" directory, it's
better to use a typedef for variable types, function types and
other usages. Other enumeration and folders will be changed to
typedef's in the future. Most of the files changed in this
commit are related to snapshot (snapshot_conf) enums.
Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
In "src/conf/" there are many enumeration (enum) declarations.
Similar to the recent cleanup to "src/util" directory, it's
better to use a typedef for variable types, function types and
other usages. Other enumeration and folders will be changed to
typedef's in the future. Most of the files changed in this
commit are related to storage (storage_conf) enums.
Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Switch over to storing of the backing chain as a recursive
virStorageSource structure.
This is a string based move. Currently the first element will be present
twice in the backing chain as currently the retrieval function stores
the parent in the newly detected chain. This will be fixed later.
